Sonar has long been used to detect waterborne or underwater objects. Sonar devices may be used to determine depth and bottom topography, detect fish or other waterborne objects, locate wreckage, etc. In this regard, due to the extreme limits on underwater visibility, sonar is typically the most accurate way to locate objects underwater. Devices such as transducer elements, or simply transducers, have been developed to produce sound or vibrations at a particular frequency that is transmitted into and through the water. Echo returns from the transmitted sound reflected off an object are received, either by the same transducers or by separate receiver elements and are converted into an electrical signal. These electrical signals can be analyzed and interpreted to obtain information about underwater structures.
Transducer technology and sonar techniques continue to evolve, such that information about larger underwater areas is being captured more rapidly. Innovations in both downscan and sidescan sonar technology have contributed to this increase in the amount of data being collected from the transducers and transducer arrays. Due to this availability of large amounts of detailed information, innovative ways to present this data can be considered and implemented.
Traditionally, sonar data has been rendered relative to the source of the sonar beam (i.e., the transducers). Since the only constant reference for the sonar data is this beam origin, renderings of sonar data can be difficult to interpret. For example, consider a transducer that is affixed to a watercraft. The transducer may continuously receive return echoes describing the underwater surroundings of the watercraft. However, by simply considering the content of the raw sonar data retrieved from a transducer, the physical movement of the watercraft is unaccounted for in the rendering of the data. Based on the raw sonar data alone, it can be unclear whether the watercraft was traveling in a straight line (e.g., due north) or if the watercraft is circling the same location. Because the only reference is the transducer or the watercraft itself, the context in which the raw sonar data is being provided can be unclear and confusing, particularly for a novice to sonar technology.
As such, it may be desirable to manage and render raw sonar data in different contexts in order to increase the interpretability of the data to a user.